Commercial and residential sinks are typically connected to a wastewater pipe system which eventually empties into a sewer system of some sort. A problem common to sinks and wastewater drain systems is that material can accumulate in the sink, its drain and/or the wastewater piping system which prevents the wastewater from advancing through the system.
The problems associated with clogged sinks and drain systems is particularly acute in commercial restaurant establishments. In these establishments, not only is a large volume of liquid processed through the wastewater system, but typically also a large amount of debris such as food particles, packaging materials, etc., is placed into the wastewater stream. Because of the narrow nature of the sink drain opening and/or the wastewater piping system, these drains and pipes repeatedly become clogged. Once the drain or the piping system becomes clogged, the time-consuming and often costly chore of removing the clog becomes necessary.
It has been found that the best way to prevent the clogs, and thus the necessity for removing the clogs, is to prevent material from entering the drain and/or the wastewater piping system.
In the past, a number of devices have been utilized to prevent unwanted material from entering the drain and/or piping system. The oldest and most common method of preventing particulate matter from entering the drain and/or piping system is to place a substantially hemispherical strainer device into the drain of a common sink. The drawbacks of this device are readily apparent.
First, the area through which the wastewater must travel is relatively limited. This results in even a small amount of particulate matter being able to clog the strainer, which in turn results in a back-up in the sink.
Second, once the liquid is backed up, the strainer must be removed by placing one's hand into the backed-up sink to pull the hemispherical-shaped strainer from the drain area. Not only is this an undesirable chore, but the end result is often also equally unacceptable. More specifically, when the dome-shaped strainer is removed from the drain area, the liquid flow rushes around and past the dome taking the debris collected on the dome down into the drain and into the piping system.
Alternative strainer systems are known which recognize the shortcomings of the hemispherical dome and attempt to present a better solution to the problem of debris entering the drain system. One such device is set forth in U.S. Pat. No. 3,713,539 issued on Jan. 30, 1973, to Thompson, et al. In this patent, a strainer device for use in drainage receptacles is set forth. The strainer device is removably mounted adjacent to the upper portion of the drainage receptacle and is adapted to captively retain foreign material entering therein. A substantially similar straining device is utilized and set forth in U.S. Pat. No. 4,321,713 issued on Mar. 30, 1982, to Thompson. In each of these devices, a flat, square frame member is utilized to support a piece of stainless steel screen. This device is a dramatic improvement over the hemispherical dome but likewise has substantial drawbacks.
First, the use of a single piece of screen material as is set forth in each of the two patents still significantly limits the surface area of the straining member. The limitation of the surface area is controlled by the amount of stretch that can be maintained in the screen itself. If the screen is stretched too much, the gaps between the wire components of the screen become too large and the screening efficiency is decreased. The inevitable end result is a relatively shallow, low surface screen.
Not only does the shallow screen result in a reduced surface area for the screen, but it also results in the straining device being able to hold only a small quantity of particulate matter. This means the screen quickly becomes filled and clogged, which necessitates repeated removal and cleaning to prevent a backup.
Still further, the prior screen devices do not include a handle or other means by which the unit can be removed from the sink area. Accordingly, the person removing the device must reach into the debris and gunk captured by the strainer to remove the strainer from the sink.
In light of the foregoing, it is an object of the present invention to provide a device for removing particulate matter from a stream of liquid. It is another object of the present invention to provide a straining device for use with residential and commercial sinks, floor sinks and roof drain systems. Still further, it is an object of this invention to provide a straining device having a large straining surface area. Yet another object of this invention is to provide a straining device which can easily be removed from the sink or receptacle in which it is used. It is yet another object of the present invention to provide a relatively large collection area for the particulate matter such that as the particulate matter builds up and prevents flow through one portion of the screening device, flow is redirected to exit the strainer through another area thereby maximizing flow for a greater period of time. It is yet another object of the present invention to provide a strainer which can be set into a floor sink in a manner such that the overlapping, flanged portion of the straining device is tapered to allow sweeping of debris into the straining device. Additionally, it is an object of the present invention to provide a grating system that can be used with the straining device should the sink be in an area of high traffic. Still further, it is an object of the present invention to provide a device that is relatively easy to manufacture and which is comparatively economical.